Irrigations systems usually include a programmable irrigation controller that turns valves ON and OFF in accordance with a watering program. The irrigation controller is typically connected to a plurality of solenoid actuated valves through field valve wires and valve common wires. Some irrigation controllers known as “decoder controllers” control a large number of valves through a single set of wires that run between all of the valves by encoding unique valve identity codes on the wires along with the power signal. Large irrigation systems installed at golf courses and parks sometimes include miles of wires buried under ground near the surface. This presents a significant challenge in terms of protecting the sensitive electronic components of the irrigation controller from power surges, because lightning strikes are attracted to the areas where the wires are buried.